Improvement in valves for direct-acting engines



C. ROGERS. j VALVES Fon DIRECTQACTING ENGINES.

No.173,063.. Patented. Feb. 1,1876.

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- 1 g ii 'Peffv'' NITED STATES "I'Dnrnlv'lf,FFIim.v 7

CHARLES ROGERS, OFVALLEGHENY, PENNSYLVANIA.

IMPRovMENT lNvALvEs Fon DIRECT-ACTING. ENGINES.

Specification forming part of Letters Patent No. l 73.063, datedFebruary 1, 1876; application -filed y November 15, 1875. v

To all whom t may concern v Be it known thatvI, CHARLES Roenes, ofAllegheny, in the county of Alleghenyand State of Pennsylvania, haveinvented certain new and useful Improvements in Valve-Gear forDirect-'Acting Engines; and I do hereby declare the following is a full,clear, and exact description -of the invention, such as'will enableothers skilled in the art to which it pertains t0 make 'and use it,reference bein-g had to the accompanying. drawings, which form part ofthis specification, in which- Y Figure 1 isahvertical.longitudinalmiddle section. Fig.2isa vertical transverse middle l section. Fig. -3isa plan View on upper face of main cylinder. Fig. 4 is a plan view onupper face of auxiliary cylinder. Fig.`5 is a perspective of one of thelevers. This invention relates to the, construction of valve-gear fordirect-actin g steam and other engines, and is designed as auimprovement on my Letters Patent No. 157 ,027,-dated November 17, 1874.I AThe present improvements' consist mainly in the devices I adopt ashereinafter fully described, whereby the operation of theauxiliarydouble-headed piston is effected by positive means, the live steamserving not only as a support to maintain it inits proper positionduring the passage of the\ ymain piston through the cylinder, but alsoserving to drive the vauxiliary piston home in casethelever is notstrucksharply enough to fully perform its work, and further. consists inthe arrangement of the various entrance and exit ports, particularlythose ofthe upper cylinder, where-y by the greatest possible amount ofwork is obtained from the steam, and the possibility of a dead-point isobViated, thus conferring the most perfect reliability on theengine towhich it is attached. Y

In the drawings herewith, A represents the main cylinder, and B itspiston, both of the usualvform. Outside A is a second cylinder,

C, withv a double-headed piston, C', and hav` ing steam and exhaustports, as hereinafter fully shown. Above this,vagain, is thes'teamchestD, in which also -works a double-headed piston D', provided' with theslide-valve D".

This vertical arrangement is merely arbitrary,

iary cylinders .A and C, neareach end, pro-1 jecting into the cylinders,-is an oscillating lever, F and F', respectively, provided with ltrunnions, which turn'in seats cut in the solid meeting faces of the twocylinders, so arranged that their line of motion is in the plane of thetwo coincident 'diameters of the cylinders. Between their ends in thevcylinder C lies the piston O', and operated by them, as shownhereinafter. The lower'ends of these levers describe an arc, whoseextreme points are inside the cylinder and at its inner facerespectively. The operation of these levers is as follows V. l l

Suppose the l-main piston B is at the right of cylinder A. Steam lcomingin behind it v drives it to the left.;v But the lower end of lever Fyprojects into 'the cylinder in its path. The piston B drives its lowerend to the left, andv its upper. to the right, which, in Vturn drivesthe piston C' to the right also, thus (by means of its connectiony withpiston D', tobe shown) cutting oifsteam from theright ofv piston B,opening exhaust-port at that side, andlive-steam port on the left ofpiston B, which then travels to the right, where the same operation isrepeated by lever F', whose lower end was projectedl into cylinder A bypiston C'. The bearing` endsv of the two f leversv are rounded off todiminish friction.` Thus a sure and effectual operation of the pistonG'lis effected-a very important result,

since the ,piston G'controls the-admission of steam and exhaust. Thiswill be seen from what follows.

.The Vpiston C' has a perforation,or an annular groove, a, near eachend, which coinmuuicate, as hereinafter shown, with ftwo other channels,b d, cut in walls of chamber C, which serve respectively as portsfor thelive .and exhaust steam 'to the ends of they chamber D, which, byoperating piston D' withv its slide-valve, regulates .the steam `formain cylinder A. Channels a, their position varied bythe stroke ofpiston C',-serve either' asf steam-port for one end, and exhaust for theotherend of chamber D, or vice versa,ra

cording as they register with channels b d and b' d'.

These` channels b d are made as follows: Channel b starts fromsteam-port E, where| it cuts through the meeting faces of chamber C andcylinder A, and in both directions longitudinally still on the meetingfaces, it continues toward both ends, near which it turns upwarddiagonally through the walls of chamber C on a diametrical line, till itemerges into chamber C. Exactly opposite this point of emergence thechannel b continues till it meets the upper face of chamber C. Then itis cut lengthwise along the face and toward the ends, near which it isturned upwardly and inwardly till-it finally opens into the ends ofchamber D. This construction, it must be remembered, is duplicate-t'.e., the two corresponding channels, b b', lead from the steamport E eachto one end of" steam-chest D.

The channels d d' are similarly constructed,

but on opposite side and in opposite directions diametrically fromchannels b b', and starting from the exhaust-port E', but leading intothe ends of steam-chest D at points further in than mouth ot' channels bb'. This is to avoid leakage, and cushion the steam on piston D'.-

Where the channelsl b d and b' d' cross the Y chamber C theyv must be sosituated that at each end of the stroke of piston G' the-chan nels awill register either with b and d', or with b' and d at the respectiveends. In other Words, they are so arranged that when piston c' is ateither limit the channels a will register with steam-port b at one endand exhaust-port c1' at the other, or with'steamport b' at one andexhaust-port d at the other end-that is to say, the steam and exhaustports for operating piston D'. According to the position of the latterits slide-valve D" admits steam to and exausts it from alter-:lately-opposite ends of cylinder A 'through steam-port E andexhaust-port E', respectively, which are the same as in my formerpatent, except that the exhaust-port E' is not open to the space aboutthe middle of piston C'. Therefore, as no leakage can occur therethe,piston C' may be lightened as much as possible by cutting its middlepart away, leaving only a thin shaft connecting the two heads, thusdiminishing friction. This lis a necessity in large engines.

The trippers F F', it is to be remarked, are specially constructed andarranged with reference to the piston C', chamber C, and piston B,sothat when driven back by the action of the piston G' the blows andpressure will be resisted by the ends of the chamber O through the headsof said `trippers, therebyfrelieving the trunnions and other parts ofthe trippers of injurious consequences.

When the trippers are constructed with shoulders on their lowerportions, through which alone the blows ot' the piston C are'to beresisted, the consequence is soon a batterwater,

ing of said shoulders, and a disturbance of the uniform action of thevalve-gear. i

The ope-ration of the whole, then, is as fol-l lows: Suppose the enginehad been stopped when piston B had just reached the extreme right, andbefore change of motion could be effected-this would leave piston C' atthe extreme left, and piston D' at the left also, whose slide-valve thenwould give open communication between steam-port E and right of cylinderA, at the same time piston C' giving steam-port to left of piston D'.Now, let on steam. It will enter behind piston B, force it to the left,and at the same time press up through the working space of lever F' tosupport piston C' during the stroke of piston B. The latter continuesits stroke to the left under pressure till it strikes lever F, whichthrows piston C' to the right. This, with grooves a by the channels b'd, opens the exi haust on the right and steam-port on left of piston D',forcing it to the right, and by means of its slide-valve D opening thesteam-V port to the left and exhaust to the right of the main piston B,and so on. No special steam-port is needed for the ends of piston C',because steam will nd its way through the working-space of levers F F'to serve the purpose of support to it. j

This is a chief point in my invention. If

the main piston move slowly it will strike the lever, but not hardenough to drive the piston C' home to the other end, thereby causingonlya small modicum of steam to enter behind the main piston. This maynot suftice to move it; but the steam-pressure extends up through theworking-space of the lever, and exerts itself in aid of the lever,shooting piston G' to the full limit instantly, which then gives moresteam to piston D', which opens the full steam area to the main piston,causing it to start in its reciprocation.

The steam is not admitted at one end till it has fully done its work atthe other, the change being effected by means that defy the condensationof steam or formation of since the devices must work whether water beformed or not. A further advau` tage is the impossibility ofdead-points.

The mere arrangement of the channels b b' d d' may be altered atpleasure, so long as they retain their alternative functions. l .Thelevers might be replaced by cams or circular rods or bolts shooting 'incircular grooves, or other equivalents suggested by" mechanical skill. y

Heretofore when attempts have been made vto effect these results bytrippers, and such` devices protruding into Vthe cylinder, theyl haveall been of such a nature as to require a strictly steam-tight joint,which, under the circumstances, is not easyr t'o effect; but by myinvention no tightness of joint is wanted.

Infact a loose joint is necessary, as will be` easily understood fromthe' foregoing;`

Having fully described my invention what vaoe i y claim, and desire tosecure by Letters Patent, is as follows: y

1. The combination, with the'chamber D and the double-headed piston- O,annularly grooved or diametrically perforated and Working in the chamberC, of the steam and eX- haust ports b b d d', registering alternately atopposite ends, said piston C being cushioned by steam entering chamber Cfrom chamber A, substantially as specified. e

2. In combination with the double-headed auxiliary piston G, operatingsubstantially as described, and the main piston B, the 1evers ortrippers F F', constructed and-located with reference to the pistonGvand the ends of chamber C, as specified, whereby theirheads willalternately strike the said ends at each full stroke of the piston G',substantially as and for the purpose specified. i

In testimony that I claim the foregoing I have hereunto setV my handthis thday of November, 1875.

Trios. J. MGTIGHE, A. GoRcoRAN.

